Z bar pivot ball broke. Common?

[67ranchhand]

Went on a slow cruise to scout for deer and while I was out and about, my clutch pedal got easier to push. Made a pop sound and two pushes later, nothing. Now my clutch pedal has always been pretty stiff and I had the z bar off to clean it and put new grease in it. But the pivot ball that threads into the engine block broke off flush with the block. Now I have to get it out of there and replace, which is no big deal, but has anyone else ever had this happen? Any idea why this happened? Thanks everyone!